Scrapy - 在脚本的上下文中打印管道数据

使用scrapyframework后，我想在我的python脚本上下文中处理我的pipeline.py输出。Scrapy - 在脚本的上下文中打印管道数据

管道输出tracks.jl，如下：

pipeline.py

class PitchforkTracks(object): 

    def __init__(self): 
     self.file = open('tracks.jl', 'wb')

是在同一script.pydirectory产生json文件：

def process_item(self, item, spider): 
     line = json.dumps(dict(item)) + "\n" 
     self.file.write(line) 
     return item

在这里，我运行scrapy。

script.py

def output(): 
    process = CrawlerProcess(get_project_settings()) 
    response = process.crawl('pitchfork_tracks', domain='pitchfork.com') 
    # the script will block here until the crawling is finished 
    process.start() 
    #process pipelined file 
    tracks = [] 
    time.sleep(5) 
    #here I pause so there is time for pipeline to build `tracks.jl` at directory 
    with open('tracks.jl', 'r+') as t: 
     for line in t: 
      tracks.append(json.loads(line)) 
    print (tracks) 

    #process lines from here on

当我打印 lines

，但是，我得到一个空list[]。

如何在python script内打印pipeline.py的输出？

编辑：

这是我log当我运行scrapy crawl pitchfork_tracks：

2016-10-03 09:28:39 [scrapy] INFO: Scrapy 1.1.2 started (bot: blogs) 
2016-10-03 09:28:39 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'blogs.spiders', 'SPIDER_MODULES': ['blogs.spiders'], 'ROBOTSTXT_OBEY': True, 'BOT_NAME': 'blogs'} 
2016-10-03 09:28:39 [scrapy] INFO: Enabled extensions: 
['scrapy.extensions.logstats.LogStats', 
'scrapy.extensions.telnet.TelnetConsole', 
'scrapy.extensions.corestats.CoreStats'] 
2016-10-03 09:28:39 [scrapy] INFO: Enabled downloader middlewares: 
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware', 
'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware', 
'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware', 
'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware', 
'scrapy.downloadermiddlewares.retry.RetryMiddleware', 
'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware', 
'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware', 
'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware', 
'scrapy.downloadermiddlewares.redirect.RedirectMiddleware', 
'scrapy.downloadermiddlewares.cookies.CookiesMiddleware', 
'scrapy.downloadermiddlewares.chunked.ChunkedTransferMiddleware', 
'scrapy.downloadermiddlewares.stats.DownloaderStats'] 
2016-10-03 09:28:39 [scrapy] INFO: Enabled spider middlewares: 
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware', 
'scrapy.spidermiddlewares.offsite.OffsiteMiddleware', 
'scrapy.spidermiddlewares.referer.RefererMiddleware', 
'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware', 
'scrapy.spidermiddlewares.depth.DepthMiddleware'] 
2016-10-03 09:28:39 [scrapy] INFO: Enabled item pipelines: 
['blogs.pipelines.PitchforkTracks', 
'blogs.pipelines.PitchforkAlbums', 
'blogs.pipelines.PitchforkReissues'] 
2016-10-03 09:28:39 [scrapy] INFO: Spider opened 
2016-10-03 09:28:39 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min) 
2016-10-03 09:28:39 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023 
2016-10-03 09:28:39 [scrapy] DEBUG: Crawled (200) <GET http://pitchfork.com/robots.txt> (referer: None) 
2016-10-03 09:28:40 [scrapy] DEBUG: Crawled (200) <GET http://pitchfork.com/reviews/best/tracks/?page=1> (referer: None) 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Moses Sumney', 'track': u'Lonely World'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Cherry Glazerr', 'track': u"Told You I'd Be With the Guys"} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Danny Brown', 
'track': u'Really Doe\u201d [ft. Kendrick Lamar, Ab-Soul, and Earl Sweatshirt]'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'NxWorries', 'track': u'Lyk Dis'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Nick Cave & the Bad Seeds', 'track': u'I Need You'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Merchandise', 'track': u'Lonesome Sound'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Weyes Blood', 'track': u'Do You Need My Love'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Kelly Lee Owens', 'track': u'CBM'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Sampha', 'track': u'Blood on Me'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Bon Iver', 'track': u'33 \u2018GOD\u2019'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Mick Jenkins', 'track': u'Drowning\u201d [ft. BADBADNOTGOOD]'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Chromatics', 'track': u'Dear Tommy'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Young Thug', 'track': u'Kanye West'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Vince Staples', 'track': u'Prima Donna\u201d [ft. A$AP Rocky]'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Angel Olsen', 'track': u'Sister'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Cass McCombs', 'track': u'Bum Bum Bum'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Hamilton Leithauser', 'track': u'A 1000 Times'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Danny Brown', 'track': u'Pneumonia'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Frank Ocean', 'track': u'Ivy'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Frank Ocean', 'track': u'Rushes'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Half Waif', 'track': u'Turn Me Around'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Rae Sremmurd', 'track': u'Black Beatles\u201d [ft. Gucci Mane]'} 
2016-10-03 09:28:40 [scrapy] DEBUG: Scraped from <200 http://pitchfork.com/reviews/best/tracks/?page=1> 
{'artist': u'Bon Iver', 
'track': u'22 (OVER S\u221e\u221eN) [Bob Moose Extended Cab Version]'} 
2016-10-03 09:28:40 [scrapy] INFO: Closing spider (finished) 
2016-10-03 09:28:40 [scrapy] INFO: Dumping Scrapy stats: 
{'downloader/request_bytes': 459, 
'downloader/request_count': 2, 
'downloader/request_method_count/GET': 2, 
'downloader/response_bytes': 22624, 
'downloader/response_count': 2, 
'downloader/response_status_count/200': 2, 
'finish_reason': 'finished', 
'finish_time': datetime.datetime(2016, 10, 3, 12, 28, 40, 425137), 
'item_scraped_count': 23, 
'log_count/DEBUG': 26, 
'log_count/INFO': 7, 
'response_received_count': 2, 
'scheduler/dequeued': 1, 
'scheduler/dequeued/memory': 1, 
'scheduler/enqueued': 1, 
'scheduler/enqueued/memory': 1, 
'start_time': datetime.datetime(2016, 10, 3, 12, 28, 39, 535638)} 
2016-10-03 09:28:40 [scrapy] INFO: Spider closed (finished)

来源

2016-10-02 data_garden

你可以运行蜘蛛作为'scrapy crawl pitchfork_tracks'并确保它写入任何内容吗？它不能是在scrapy写入之前打开文件，因为脚本将被阻塞在'process.start（）'行直到抓取完成。所以在这里看来，你的蜘蛛没有保存任何东西，我没有看到你的管道问题，所以一定有一些错误。尝试'scrapy抓取myspider 2>＆1> output.log'。 – Granitosaurus

@Granitosaurus的确在写作。请参阅我对该问题的编辑，我已经为您打印了抓取。 –

我想这是因为你从来没有管道关闭的文件对象。您应该在管道的open_spider()方法中打开一个文件，并在close_spider()方法中关闭它。

class PitchforkTracks(object): 

    def open_spider(self, spider): 
     self.file = open('tracks.jl', 'wb') 

    def close_spider(self, spider): 
     self.file.close() 

    def process_item(self, item, spider): 
     line = json.dumps(dict(item)) + "\n" 
     self.file.write(line) 
     return item

来源

2016-10-03 14:31:04 Granitosaurus

做到了！万分感谢。 –

Scrapy - 在脚本的上下文中打印管道数据

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